Heat pump heating and refrigerating system

The invention discloses a heat pump heating and refrigerating system which comprises a heat pump shell, a mounting cavity is formed in the heat pump shell, a refrigerating system and a buffer water tank are mounted in the mounting cavity, and a water outlet and a water return port are formed in the heat pump shell; the water outlet is communicated with the buffer water tank through an eduction tube assembly; the double-pipe heat exchanger comprises a heat exchange inner pipe and a heat exchange outer pipe, the heat exchange inner pipe is arranged in the heat exchange outer pipe in a penetrating mode, and the double-pipe heat exchanger is installed in the buffer water tank; one end of the heat exchange inner pipe extends out of the buffer water tank and is communicated with the outlet end of the refrigerating system, and the other end of the heat exchange inner pipe extends out of the buffer water tank and is communicated with the inlet end of the refrigerating system; one end of the heat exchange outer pipe i